The present invention relates to a process for flame- and fireproofing surfaces, substrates, and materials of various and diverse composition, comprising natural, synthetic and metallic materials. The invention relates more particularly to the readily achievable application of an intumescent fire- and flame retarding composition to coat smooth, non-porous, as well as porous surfaces. The invention further discloses a novel fire- and flame retarding composition based on dissolving soluble materials dispersing and suspending insoluble materials colloidally in a colloidal solvent, and further describes procedures for modifying the polarity of said flame retarding composition, where needed, to achieve the desired coating effect on synthetic and metallic surfaces. Furthermore, the composition herein disclosed is comprises non-toxic materials.
In the prior art it is almost always specified what kind of material the retardant is to be applied to, with substantial differences in composition depending on the actual substrate to be protected.
Furthermore, in most cases the materials to be applied are unsafe, toxic or noxious, making them unsuitable for househeold use or for other purposes which entail human contact or handling; furthermore, their preparation and/or application may entail cumbersome and involved techniques. Presently published fire retardant literature does not disclose the need to keep the fire retardant mixtures in suspension as colloidal mixture to obtain the desired fire protecting quality of a mixture, and to increase and enhance the shelf-life of the product
Currently there is no single intumescent-based fire-retardant coating material having all of the following features:
1. a coating material allowing ease of application by spraying, brushing, roller application, or the like; and,
2. a coating material maintaining its consistency over time and keeping all of its components perfectly mixed and blended with one another in a colloid state; and,
3. a coating material that can be applied with minor variations to a large variety and diversity of substrates;
4. a coating material comprising non-toxic or minimally toxic ingredients;
5. a coating material that is suspended in a water based solvent to be non-toxic or having no toxicity when applied, after curing on all kinds of surfaces, including wood, plastics, sheetrock, toys, formica, rubber, etc.; and,
6. a coating material providing a low rate of thermal transmission, especially where low weight is critical, such as in aircraft and ships;
7. a coating material drying quickly and efficiently;
8. a coating material with good adhesion and stability.
9. a coating material for home and non-professional use.
10. a coating material for incorporation and application in building materials and structures.
None of the so-far disclosed flame retardant compositions teach the process and principles outlined in the present application. U.S. Pat. No. 4,198,328, issued to Bertelli, discloses flame-resisting paints obtained by reacting aldehydes with compounds containing amido, carbonyl ( greater than Cxe2x95x90O), and  greater than Cxe2x95x90S containing compounds inserted in a cyclic structure, or reaction products from aliphatic or aromatic diisocyanates or triisocyanates with organic compounds having reactive hydrogen atoms. U.S. Pat. No. 4,224.374, issued to Priest, discloses a non-flammable impregnant for polyether-derived polyurethane foam substrates, characterized by a carboxylated neoprene latex and alumina trihydrate. U.S. Pat. No. 4,370,442, issued to Pearson, discloses an aqueous resinous system produced by reacting an aldehyde with phosphoric acid, and adding an alkanolamine, urea, and melamine in aqueous solution. U.S. Pat. Nos. 4,380,593 and 4,740,527 issued to Von Bonin, disclose intumescent products obtained by a complex reaction sequence employing polyisocyanates as starting materials. U.S. Pat. No. 4,663,226, issued to Vajs et al., discloses a flexible coating providing protection up to 1000xc2x0 C., obtained in two stages; a first stage produces an intumescent foam layer and the second relies on vitrification of an agent carried in the intumescent layer, preferably a silicic base. U.S. Pat No. 4,879,320, issued to Hastings, disclose a fluid intumescent film-forming binder such as polyvinyl acetate, acrylic resin, vinyl acrylic resin, silicone resin, epoxy or polyurethane, or combinations thereof, that can be rendered electrically conductive by incorporating conductive particles. U.S. Pat. No. 5,401,793, issued to Kobayashi, discloses the use of carbides, borides, nitrides, synthetic resins containing phosphorus and/or sulphur, and other compounds capable of forming Lewis bases on heating. U.S. Pat. No. 5,723,515, issued to Gottfried, discloses a fluid intumescent base material, which additionally includes a binding agent, solvents, and pigment, with the addition of flame spread, oxygen and thermal transmission reducing materials, refractory fibers, mechanical enhancers, water resistant and elasticity agents.
Furthermore, none of the currently disclosed flame retardant composition teaches the use of colloid forming compositions to obtain a stable, paste-like, easy to apply flame suppressant and fire retardant product.
1) In accordance with the above stated needs and the prior art it is the object of the present invention to disclose unique fire retardant procedures, to apply fire retardant mixtures to a whole variety of solid surfaces, equally effective on wood, paper, styrofoam, polystyrene, rubber tubing, vinyl tubing, PVC tubing, iron, steel, stainless steel, aluminum and other non-ferrous metals, etc.
2) Another object of the present invention is to disclose a flame retardant mixture consisting of an intumescent base comprised of water soluble materials dissolved in a colloidal solution, and water insoluble materials dispersed or suspended in colloidal form in said colloidal solution. The colloidal solution is formed dissolving macromolecular materialsxe2x80x94such as carbohydrates and proteinsxe2x80x94in water prior to the addition of any further materials. The purpose of colloidally dissolving, dispersing, and suspending materials is to keep the fire retardant mixture evenly distributed, and permanently suspended, thus avoiding precipitation of the insoluble material during storage, application, and providing a uniform flame and fire retardant coating.
Intumescent fire retardant mixtures comprise a source of phosphoric acid, a charring agent, and a blowing agent. Upon exposure to fire, phosphoric acid is generated, which catalyzes the formation of a char layer and the generation of non combustible gases which oppose the supply of oxygen to the fire. The surface char layer both insulates from further thermal degradation and impedes the flow of potentially flammable decomposition products from the interior of the product to the gas phase where combustion occurs. Intumescent mixtures further interfere with the supply of oxygen to the flame by blowing non-combustible gases generated by the fire and flame themselves, thus causing the flame to eventually subside and die.
3) Another object of this invention is to disclose a paste-like, colloidally stabilized, flame retardant mixture, wherein fillers, and elasticity agents such as milled fibers, paper, vermiculite, perlite, and the like, are added to give a paste like consistency to the mixture; said mixture also including fire and heat refractory fibers and materials, flame spread reagents, thermal transmission agents, and oxygen reducing agents, to provide protection at elevated temperatures, as high as 3500-4000xc2x0 F.
4) A feature of the present invention is a colloidal fire retardant mixture that can be mixed with a water based resin, that , upon curing at room temperature, with or without addition of an accelerator, adheres to synthetic substrates, previously impervious to the application of the original flame retardant mixture.
5) Another object of the present invention is to disclose a process to apply a replacement fireproofing cementitious compound for steel structures, pipes, etc. fire retardant mixture on a variety of substrate materials, such as wood, plywood, formica, plastics, PVC, rubber, composites, vinyl, styrofoam, sheetrock, ceiling, tiles, etc. Cementitious fireproofing materials are substitutes for asbestos, when asbestos is removed.
6) A further feature of the present invention is to disclose a process to apply a fire retardant materials for use in many industries, such as construction, transportation, utilities, telecommunications, chemical and petroleum manufacturing, aircraft, marine crafts, industrial, domestic and military applications.
7) A further feature of the present invention is to disclose a process using non-toxic products.
Accordingly, one of the advantages of the present invention is that it provides for a stable intumescent fire retardant coating composition that is effective on a variety of solid substrates that display different chemical interactions with the fire retardant.
Another advantage of the present invention is that the stability of the intumescent base is made possible by the formation of a thick colloidal mixture which keeps insoluble particles hydrated and suspended in the solution. As a matter of fact, the full stabilization of the mixture requires 3-5 days to take effect.
Another advantage of the present invention is that the applicability of the rather polar intumescent mixture for synthetic and non-polar surfaces is obtained through the application of an alkaline water based resin, which decreases the ionic character and polarity of the mixture. The resin itself, dispersed in the mixture, polymerizes slowly and gradually at room temperature creating a loose molecular network which envelopes the intumescent material. The more polar groups of the resin appear to be turned inwards while the less polar groups of the resin are turned outwards towards the unpolar substrate, thus binding to it by hydrophobic and Van der Waals bonds. Another advantage of the present invention is that it allows for the addition of colored pigments, so that the paste can be used as paint for decorative purposes in homes, business and industrial settings.
Yet another advantage of the present invention is that is that a similar combination can be used in glues, so that fire retardant glues can be produced.